Oscillatory switch



P 18, 1956 c. VAZQUEZ 2,763,740

OSCILLATORY SWITCH Filed Feb. 17, 1953 2 Sheets-Sheet 1 I H P I P! l 5 g I [NYE/V708 flai fi 74 ?4 15 zQ f Sept. 18, 1956 c. VAZQUEZ 2,763,740 OSCILLATORY SWITCH Filed Feb. 17, 195; 2 Sheets-Sheet 2 WFM United States OSCILLATORY swrrcn Charles Vazquez, Paris, France,

Iudustrielle des tion of France assiguor to Compagnie Telephones, Paris, France, a corpora- The present invention relates to improvements in electromagnetic buzzers comprising a vibrating strip, called an oscillolame adapted to be used as time base, for use in particular in telecommunication systems.

The buzzer which is the object of the present invention is characterised in this that it comprises a device for regulating the frequency of oscillation of the oscillating strip, said device comprising an elastic member which exerts an adjustable pull on the oscillating strip along its axis.

In order to eliminate the interference oscillations of the oscillating strip, the latter is gripped over a portion of its length between two small rigid plates.

In order to prevent the transmission of interference vibrations from the oscillating strip to the contact pieces, any mechanical connection between the oscillating strip and the contact pieces is eliminated. For this purpose the movable contacts are carried by two fiat springs arranged on either side of the oscillating strip and separated from their operative position by two lugs fixed on the oscillating strip, these springs being alternately released when the strip oscillates and closing, by their elasticity, the contacts of the buzzer.

Other features of the invention will appear in the description given hereafter, with reference to the attached drawing which shows as a non-limitative example, an embodiment of a buzzer constructed in accordance with the invention:

Fig. 1 shows diagrammatically the device for adjusting the frequency of the vibrating strip;

Fig. 2 is a view of the contacts of the buzzer in the normal state;

Fig. 3 is a corresponding view to Fig. 2 with a make contact;

Figs. 4 and 5 show an embodiment of the vibrating strip;

Figs. 6 and 7 show two views of the electromagnetic buzzer according to the invention.

According to Fig. l, the frequency-regulating device comprises a traction spring a placed in such a way that its longitudinal axis coincides with that of the vibrating strip b in the normal position. One of its ends is fixed to the vibrating strip at c and the other is integral with the frame d by means of a device intended to eliminate mechanical play, composed of the connection 2 the flexion spring fixed to the frame at g and an adjusting screw 11.

The spring 7 has a strong tension which pulls it towards the screw 11 against which it is held constantly resting, so that the state of elongation of the spring a and consequently the pull which it exerts on the strip, depends on the position of the adjusting screw h.

The force of the spring a intervenes in the oscillatory frequency of the whole, by its component tangent to the trajectory of the connection 0 which is added to the return couple of the strip only, this having the effect of an increase of the frequency.

Consequently when the adjusting screw 11 is tightened, the frequency of oscillation of the system decreases in a continuous and inverse manner in proportions preatent O 2,753,740 Patented Sept. 18, 1956 ice determined by a judicious choice of the constant of the spring and of the oscillating strip.

It should be noted that this device makes it possible to adjust the frequency of the system to a given standard frequency, while the apparatus is in oscillation, which has advantages from the standpoint of saving time.

Figs. 2 and 3 show the arrangement of the electrical make contacts. L and L are two flat springs, arranged on either side of the oscillating strip, having at their ends a contact cap of precious metal j and j intended to establish the electric contact with the screws k and k. These springs are fixed to the frame at m and m and have a tension which tends to separate them from the strip b but they are held by two lugs I and I fixed to the strip, so that, when the system is in the normal condition, the contacts are held open, the spacing being adjustable by the screws k and It.

When the strip begins to oscillate, the contacts j and j are alternately applied to the corresponding screws with a pressure independent of the position of the oscillating strip and without direct mechanical connection with the latter.

These contacts make it possible to obtain perfectly cut electrical signals, without interfering vibrations, owing to the fact that, on the one hand, the contact pressure is uniform and passes suddenly from zero to a given value, adjustable by bending the springs L and L and, on the other hand, the fact that the interference vibrations of the oscillating strip, subjected to impacts, are not transmitted to the contacts.

The angle formed by the springs L and L with the strip 1) is chosen with a view to minimising the relative displacement of the contacts j and j in relation to the lugs I and I and thus to reducing friction between these two parts.

Figs. 4 and 5 show an embodiment of the vibrating spring and of the fixing of the traction spring on the latter. The elastic portion of the oscillating strip is lo cated near the casing. For this purpose, two rigid small plates P and P grip the strip b over nearly the whole of its length, only leaving it free in a small space n located between the holding lugs I and I and the casing, according to Fig. 4. The elastic deformation only occurs at this point.

An arrangement of this kind has the advantage that practically it is only deformed in a plane containing the axis of the strip, thus eliminating interference oscillations of twisting and hairpin bends which are found with a completely supple strip.

In order that the action of the spring a may only produce the minimum damping in the regime of free oscillation of the vibrating strip, the strip b is axially notched to permit the passage of the connecting wire of the spring a which is fixed at t on said strip as near as possible to the flexible part n of the oscillating strip. The deadhead of the oscillating strip is provided with an axial cavity sufficient not to brake the oscillations of the vibrating strip.

Figs. 6 and 7 show an embodiment of the complete apparatus, provided, as is known, with a framework q, a coil r and a blade s.

The buzzer operates in the following manner:

The device is set when the coil r attracts its blade s which drives the oscillating strip b by means of an arm ending in a pusher.

When the coil releases its blade, the oscillating strip is freed and sets up free oscillations with a sufficient amplitude for the contacts J, J to he applied alternately to the screws k, k.

What is claimed is:

1. An oscillatory switch comprising, in combination,

oscillatory member, associated with said hammer for actuating said hammer.

supporting means; stationary contact means mounted on said supporting means; movable contact means mounted on said supporting means movable between an open position spaced from said stationary contact means and a closed position engaging said stationary contact means spring bias means secured between said supporting means; and said movable contact means and tending to move the latter from said open to said closed position; an elongated oscillatory member mounted at one end on said supporting means so as to periodically engage during its oscillation said movable contact means and move it periodically from its closed into its open position, permitting said movable contact means to return by itself, after each such periodic opening movement, from its open to its closed position, said elongated oscillatory member comprising a first relatively small resilient portion close to said one end thereof and a relatively long inflexible portion extending beyond said resilient portion to the other end of said oscillatory member, said oscil-v latory member having a rest position; engaging means mounted on said oscillatory member adapted to engage said movable contact means and maintain the same in said open position when said oscillatory member is in its rest position; and means for adjusting the oscillatory frequency of said elongated oscillatory member comprising spring means extending between said other end of said oscillatory member and said supporting means,

and means for adjusting the tension of said spring means.

2. An oscillatory switch comprising, in combination, supporting means; stationary contact means mounted on said supporting means; movable contact means mounted on said supporting means movable between an open position spaced from said stationary contact means and a closed position engaging said stationary contact means; spring bias means secured between said supporting means and said movable contact means and tending to move the latter from said open to said closed position; an elongated oscillatory member mounted at one end on said supporting means so as to periodically engage during its oscillation said movable contact means and move it periodically from its closed into its open position, permitting said movable contact means to return by itself, after each such periodic opening movement, from its open to 'its closed position, said elongated oscillatory member comprising afirst relatively small resilient portion close to said one end thereof and a relatively long inflexible portion extending beyond said resilient portion to the other end of said oscillatory member; means for adjusting the oscillatory frequency of said elongated oscillatory member'comprising spring means extending between said other end of said oscillatory member and said supporting means,

"and means for adjusting the tension of said spring means; and means for actuating said elongated oscillatory member including a movable hammer mounted on said supporting means and adapted when actuated to strike said and magnetic means operative- 3.I'An' oscillatory double switch comprising, in combination, supporting means; an elongated oscillatory me'mber secured at one end thereof to said supporting means, said oscillatory member comprising a first relatively small resilient portion close to said one end thereof,

where elastic deformation occurs during the oscillation of said oscillatory member, and a relatively long inflexible portion extending from the end of said resilient portion to the other end of said oscillatory member; a pair of lug members secured to the end of said inflexible portion of said oscillatory member close to said resilient portion thereof; a pair of stationary contact means mounted on said supporting means; a pair of movable contact means mounted on said supporting means, each movable between an open position spaced from -its corresponding stationary contact means and a closed position engaging its corresponding first contact means; and apair of spring bias means respectively secured at one end thereof to said supporting means and engaging at the other end thereof said pair of lug members respectively, when said oscillatory member is in a position of rest, said pair of movable contact means being respectively mounted on said pair of spring bias means, said spring bias means maintaining both of said movable contact means spaced from said stationary contact means when said oscillatory member is in its rest position, and tending to move one of said movable contact means into periodic engagement with the stationary contact means associated therewith during the oscillation of said oscillatory member in one direction, and to move said other movable contact means into periodic engagement with said other stationary contact means during the oscillation of said oscillatory member in its other direction.

4. An oscillatory double switch comprising, in combination, supporting means; an elongated oscillatory member secured at one end thereof to said supporting means, said oscillatory member comprising a first rela* tively small resilient portion close to said one end thereof, where elastic deformation occurs during the oscillation of said oscillatory member, and a relatively long inflexible portion extending from the end of said resilient portion to the other end of said oscillatory member; a pair of lug members secured to the end of said inflexible portion of said oscillatory member close to said resilient portion thereof; a pair of stationary contact means mounted on said supporting means; a pair of movable contact means mounted on said supporting means, each movable between an open position spaced from its corresponding stationary contact means and a closed position engaging its corresponding first contact means; a pair of spring bias means respectively secured at one end thereof to said supporting means and engaging at the other end thereof said pair of lug members respectively, when said oscillatory member is in a position of rest, said pair of movable contact means being respectively mounted on said pair of spring bias means, said spring bias means maintaining both of said movable contact means spaced from said fixed contact means when said oscillatory member is in its rest position, and tending to move one of said movable contact means into periodic engagement with the stationary contact means associated therewith during the oscillation of said oscillatory member in one direction, and to move said other movable contact means into periodic engagement with said other stationary contact means during the oscillation of said oscillatory member in its other direction; a flexible arm portion secured to said supporting means; spring means extending from said other end of said oscillatory member in the axial direction of said oscillatory member when the latter is in its rest position to said flexible arm portion; and means mounted on said supporting means for moving said flexible arm portion toward and away from said oscillatory member so as to adjust the tension of said spring means and thereby adjust the frequency of said oscillatory member.

References Cited in the file of this patent UNITED STATES PATENTS 367,270 Colman July 26, 1887 887,681 Maxstadt et al May 12, 1908 1,048,670 Fessenden Dec. 31, 1912 1,336,143 Kettering Apr. 6, 1920 1,446,780 Balzer et al Feb. 27, 1923 2,075,499 Buch et al. Mar. 30, 1937 2,433,740 Collins et al. Dec. 30, 1947 2,463,426 Ressler et al Mar. 1, 1949 2,532,274 Side Nov. 28, 1950 2,618,717 Westin Nov. 18, 1952 FOREIGN PATENTS 386,943 France Apr. 25, 1908 

